Published by: Ingrid King. Last Updated on: October 31, 2022 by Crystal Uys


There is no question that vaccines protect against disease, but they also present considerable risk. Far too many cats are still being over-vaccinated because too cat guardians, still think annual “shots” are necessary, and sadly, far too many veterinarians still recommend them. This is a complex issue, and it’s up to cat guardians to educate themselves so they can make the best decision for their feline family members.

Which vaccines should your cat get?

The American Association of Feline Practitioners (AAFP) recently updated its vaccination guidelines. The guidelines divide vaccines into core and non-core vaccines, and recommended that vaccination protocols should be tailored to the individual cat’s health and lifestyle.

There are no easy, yes or no answers when it comes to which vaccines your cat should get. It depends on your cat’s age, health status, and lifestyle. It also requires weighing the benefits of vaccines against the risks. Two feline veterinarians who I trust completely have written outstanding articles on this topic, and I urge you to read both articles.

Feline veterinarian Fern Crist, DVM, provides a comprehensive overview of the available feline vaccines, and which ones your cat needs in Feline Vaccinations: Walking Through the Minefield.

Lisa Pierson, DVM, the founder of, addresses key issues associated with vaccines in Vaccines for Cats: We Need to Stop Overvaccinating.

Vaccine risks

Vaccines are implicated in triggering various immune-mediated and other chronic disorders. This is also referred to as vaccinosis. Vaccines are also implicated in the high incidence of vaccine-induced sarcomas in cats.

Dr. Karen Becker provides a detailed explanation of vaccinosis in her article Dog and Cat Vaccines are not Harmless Preventive Medicine.

Vaccines are also implicated in injection-site sarcomas. These tumors of the connective tissues are often called fibrosarcomas, and are most frequently located between the shoulder blades, in the hip region, and in the back legs. They are most often associated with inactive killed rabies or feline leukemia vaccines, or with multiple vaccines given at the same time, but they can also be caused by other injections such as steroids. The incidence of these tumors ranges from 1 in 1000 to 1 in 10,000 cats. They can develop as quickly as 4 weeks or as late as 10 years post vaccination.

Always demand non-adjuvanted vaccines for cats

Adjuvants are substances that are added to vaccines to alert the immune system that an antigen is present. They increase the immune response. Unfortunately, these adjuvants are also implicated in causing injection site sarcomas. Do not assume that your vet is using non-adjuvanted vaccines – ask before you allow any vaccine to be given to your cat.

Should you vaccinate your adult cat against distemper?

There is some compelling evidence coming from a study conducted at The Center for Companion Animal Studies at Colorado State University that shows that the common FVRCP (feline viral rhinotracheitis, calicivirus and paneleukopenia) vaccine may cause long-term damage to cats’ kidneys that increases with every booster. Click here for more information on whether you should have your cat’s distemper vaccine boostered every three years.

Vaccine titers as an alternative to over-vaccinating

Titer testing for a particular infectious agent measures the presence and level of antibodies in an animal’s blood. These antibodies reflect the combination of any natural exposure and vaccination, and were created when the animal’s immune system responded to the antigens introduced into his body. The presence of a measurable serum antibody titer indicates the presence of “immune memory”, and signifies protection from disease.

For more information on vaccine titers, please read Dr. Jean Dodd’s article Let’s Talk Titers: Avoid Over-Vaccinating Your Cat.

Rabies vaccine: it’s the law

Almost all municipalities in the United States require rabies vaccinations for all cats, regardless of whether they’re indoor or outdoor cats. I’m not aware of any municipalities that accept rabies titers in lieu of a vaccine. The required frequency of rabies vaccines is set by local jurisdictions, and doesn’t appear to have much to do with the actual immunity duration of the vaccine. The Rabies Challenge Fund is hoping to change this by determining the true duration of immunity conveyed by rabies vaccines.

In order to minimize the risk that comes with each rabies vaccine while still complying with local laws, make sure that your veterinarian only uses the non-adjuvanted Purevax vaccine manufactured by Merial. This vaccine is the only non-adjuvanted rabies vaccine on the market, and comes in a 1-year and 3-year version. If your veterinarian doesn’t carry this vaccine, insist that they order it, or find a vet who does use it.

Before you agree to have your cat vaccinated, educate yourself about all aspects of this issue, and make an informed decision.

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38 Comments on Vaccines for Cats: What You Need to Know

  1. On several sites I have seen recommendations for vaccine schedules for cats that are strictly indoors that suggest that after the initial kitten vaccinations and adult titer testing, no further vaccinations are required. But I would like to know a reasonable approach for mixed households – those with cats that are strictly indoors, but also a cat or two that are indoor/outdoor. Should more frequent vaccinations be considered in those cases?

    • I would discuss this with your vet so the protocols can be tailored to your cats’ individual situations. At a minimum, all cats would need a rabies vaccine, which is required by law anyway.

      • I always get rabies. I end up in disagreements with my vet all the time because I don’t want to continually get FVRCP every three years. If all cats were indoor only, then I would never get FVRCP for them again. But two cats are indoor/outdoor. If they are properly immunized, then I would think they still shouldn’t need them ever again. But all the minimal vaccine sites only specify for indoor only cats.

        • I know it’s frustrating. I think the bigger concern for indoor/outdoor cats is the Feline Leukemia vaccine.

          • They have been vaccinated for that – regularly for years now, but that also I have stopped.

  2. Thanks for the article. I have a question about vaccination. How long the cat can get vaccination after recover from feline panleukopenia?

    • I would discuss this with your vet, Ted. Once a cat recovers from panleukopenia, he/she generally will not develop the disease a second time. If you’re concerned about your cat’s level of protection, you can have your vet run a titer blood test.

  3. Bookmarking this for sure! I just had 3 of my 4 cats vaccinated. The first one, I didn’t go with the Purevax because I was unaware of it beforehand. I wanted to research it first and now I wish I had gotten it, but the vet tech was being so pushy that I felt uncomfortable. I definitely will go with it in 3 years. My tortie didn’t react well to the Purevax, she wasn’t completely herself again for a full week. But, it also could have been a reaction to the additional Distemper shot (or the combo of both), which I plan to read up on now because I’m not sure I want her getting that one anymore. Anyway, thank you for this informative post because it’s not easy trying to research these topics.

    • I’m glad this post helped, Kathie. One thing to keep in mind for your tortie, is to never give more than one vaccine at a time. It’s too much for the immune system to handle, which probably explained why she wasn’t herself for a week following the vaccines. And FWIW: a pushy vet tech, or vet, for that matter, is never okay!

  4. My pet has been diagnosed with CKD. Sky is going to be 8 July…2017. He is due for FVRCP and Rabies Vaccination, however I don’t think I want him to have either? Please advise.

    • You’ll need to discuss this with your vet, but I would not recommend vaccinating a sick cat, Violet. Most holistically oriented vets won’t recommend vaccinating sick cats.

    • Reluctantly, I let Sky have the FVRCP Vaccine however I would not let him have the rabie vaccine. Sky has never had High Blood Pressure but developed this shortly after his Vaccination. I do realize this may be associated to the kidney disease, but I am not entirely sure. Sky is now on medication to control and lower his B.P. I am lost to what I should do! Do I continue with his meds? I don’t want to expedite his illness.

        • Thank you. My Vet is very good with Sky, so I would keep her in the loop. I just cannot get pass that the b.p. wemt so high just after the vaccine. I also mentioned to her that when Cisco my other let had his vaccine 1 1/2hears ago….Shortly after his Vaccination he became extremy aggressive with myself and Sky without provocation. This behavior slowly tapered off and has at present ceased. It is worth mentioning that he is a gentle cat, so this change in behavior was alarming.
          I don’t know if Sky will make to his next vaccination ..but he will not be getting anymore and that goes for Cisco as well. They are indoor cats. We have a huge enclosed backyard so they do have fresh air bit I am with them at all times.This is a very informative Web site…thank you once again…

        • Thank you. My Vet is very good with Sky, so I would keep her in the loop. I just cannot get pass that the b.p. went so high just after the vaccine. I also mentioned to her that when Cisco my other pet had his vaccine 1 1/2hears ago….Shortly after his Vaccination he became extremy aggressive with myself and Sky without provocation. This behavior slowly tapered off and has at present ceased. It is worth mentioning that he is a gentle cat, so this change in behavior was alarming.
          I don’t know if Sky will make to his next vaccination ..but he will not be getting anymore and that goes for Cisco as well. They are indoor cats. We have a huge enclosed backyard so they do have fresh air but I am with them at all times.This is a very informative Web site…thank you once again…

  5. One thing I want to add. Those of us who live in the areas where Rabies is state law and who can afford (and are willing) to pay 3 times the cost of one year Purevax for the 3 year variety, should bring up the issue to our vets. It’s virtually impossible to find a vet that carries it. One issue is the cost and the need to buy 25 doses up front – i.e. if they don’t sell all of it before expiration because people don’t want it, they’ll lose money. Others say it’s too new. I even met one that lied to me and told me it makes cats sick. I think cat owners should bug their vets to carry it since if there is more interest, more vets will carry it. I find it really frustrating – in my area I couldn’t find a single vet that would carry it.

    • I completely agree: the 3-year rabies vaccine is the best choice for cats, and vets need to start carrying it for cat guardians who want their cats to have it. The 3-year-vaccine has been available for more than a year now, and the consensus among veterinarians who have used it appears to be that while there seems to be a slightly higher risk of a systemic reaction than with the 1-year product due to the higher antigen load, the amount of reactivity at the injection site does not appear to be any different. Some vets report a slightly higher incidence of injection site soreness and malaise for 24-48 hours following the injection as compared to the 1-year product.

      • Thank you very much for the reply. I didn’t see it earlier. I was really curious about the side effects parts. Wish I could find a vet in my area that carries it.

  6. Thanks for this article. One of my cats is allergic to the rabies vaccine, and her reaction has gotten worse with every booster. With her last one, she had seizures for a day – and that was with Purevax. She’s not due for another year, but I don’t think I can give her one more rabies shot ever. My other two cats, including her full brother, are fine with the rabies shot.

    • That’s a frightening reaction, Aimee. I don’t think I’d give her another rabies vaccine. Ask your vet to write a medical exception letter so you have something on file should it ever become an issue. Not all municipalities will recognize exception letters in lieu of a vaccine, but it can’t hurt to have one on record with your vet.

      • Don’t the bottles have a warning about administering to ill or compromised cats? Aimee’s cat would certainly fall under those guidelines.

        • They do – but that still doesn’t guarantee that local municipalities would accept that as a valid reason for a lapsed rabies vaccine.

          • Thank you for the idea about the letter; I talked to my husband and he says no more rabies vaccines for her ever!

    • My cat has had the same bad reaction to the rabies shot. I’ll never let her have another one no matter the law

  7. I’ve definitely been minimizing vaccinations on my cats over the years, and fortunately my vets have been accepting of my decision. One of my favorite articles on vaccination is by Dr. Don Hamilton. I’ve cited it for years, and of course, Dr. Jean Dodds has been doing great work.

  8. well said. we have to do rabies due to the law around here but do it every 3 years. the only other vaccine we get is FVRCP and mom keeps those current due to our active foster status….at least to a certain age and then she talks to our vet about continuing

  9. Excellent post. I only do rabies every 3 years because it is the law. I feel bad or states that require it yearly which is ridiculous.

    • Just to clarify, Ellen: while rabies requirements do vary by state, the frequency is typically governed by the vaccine given. Some vaccines are labeled for three years, some for one year. As stressed in the article, the only three-year rabies vaccine that should ever be given to cats is the Merial Purevax product, which has only been on the market for a little over a year.

      • I am so happy I ran into this article. The information is very useful. Can you please explain the difference betveen PUREVAX and IMRAB rabies vaccines, both by Merial? Are they are the same? I would really appreciate it.

        • No, they are not the same. Purevax is the only vaccine you should use for cats, since it’s non-adjuvanted. Imrab contains an adjuvant. Adjuvanted vaccines have been linked to feline fibrosarcomas.

  10. There is certainly a lot to consider here. I was always told that cats need the FVRCP vaccine every three years, but it doesn’t look like that’s necessarily the case. I’ll have to do some further reading. My babies are due for their next rabies vaccine in 2017. I’ll bookmark this so I can refer back to it. Thank you for sharing all of this information!

  11. Thank you for this information, Ingrid. Our kitty Anya (an indoor only cat) will be due for a rabies vaccination this May, and this article really helps us know how to deal with this issue that I’ve been very concerned about. Very timely. Thank you!

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